Renewable fuse



' Jung 16, 1924.

. 1,497,323 H. E. BUTLER RENEWABLE FUSE Filed Jan. 19, 1923 ihventnrHenry E, Butler;

Patented June 10, 1924.

UNITED STATES PATENT OFFICE.

HENRY BUTLER, OF SCHENECTADY, NEW YORK, ASSIGNOB TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

RENEWABLE FUSE.

Application filed January 19, 1923.

T all whom it may concern:

Be it known that I, HENRY E. BUTLER, a citizen of the United States,residing at Schenectady, in the county of Schenectady, State of NewYork, have invented certain new and useful Improvements in RenewableFuses, of whichthe following is a specification.

My present invention relates to renewable plug fuses suchas are used inhousehold lighting-circuits and has for its object to provide animproved renewable fuse which is simple in structure, permits of a largenumber of renewals and can be manufactured at a low cost; also one inwhich the fuse wire or ribbon can be quickly and easily changed. 7

For a consideration of what I believe to be novel and my invention,attention is directed to the accompanying specification and the claimsappended thereto.

In the drawing, Fig. 1 is a perspective View of a fuse plug embodying myinvention; Fig. 2 is a sectional view thereof; Fig. 3 is a perspectiveview of the base of the fuse plug; Fig. 4 is a perspective view of thefuse carrier; Fig. 5 is a perspective view of the cap of the fuse plug,and Fig. 6 is a perspective View of the fuse carrier showing the fusewire or ribbon in another position.

Referring to the drawing, the base of the fuse plug comprises a block 10of insulating material provided on its outer surface with a metal shell11 in the form of screw threads adapting the base to screw intolastandard fuse receptacle. Block 10 is provided with a central-chamber 12in which is located post 13. Extending through post 13 ,is a

conductor 14 which electrically connects an outside contact 15 with aninside contact16, the latter being located on the end of post 13. Shell11 and contact 15 form the usual fuse plug terminals which are connectedby the fuse wire or ribbon. The outer end of block 10 is enlargedsomewhat as indicated at 17 and is threaded on its outer surface toreceive a cap 18 provided with a window in the form of an opening 19covered by a piece of suitable transparent material 20 such as isordinarily used in fuse plugs. In the inner surface of the enlargedouter end of block 10 is a recess 21 in which is located a springcontact 22 electrically connected to shell 11. It may be formed as aextending parallel thereto.

Serial No, 613,564.

separate piece soldered or otherwise c011- nected to shell 11 or it maybe formed as an integral part of shell 11. Formed in block 10 adjacentto itsouter end is an annular shoulder 23.

The fuse wire carrier comprises a block 24 ofinsulating material with aflange 25 at its outer end which seats on the outer end of block 10 anda shoulder 26 which engages. shoulder 23 in block 10. The inner end ofblock 24 fits recess 12 in block 10 and is provided with a recess 27which receives post 13. Preferably post 13 and recess 27 aremaderectangular so the fuse carrier cannot be twisted relatively to thebase. In the outer end of block 24: is a cavity 28 and directly beneathflange 25 is an opening 28 which communicates with cavity 28. Cavity 28is adapted to receive a roll or package of fuse material 29 one end ofwhich extends through opening 28*, thence along the outer surface ofblock 2%. and into recess 27 where it is held by post 13 in engagementwith contact 16. At the side of block 2% spring contact 22 engages thefuse material as shown in Fig. 2, the fuse material thus connectingcontact 15 [to shell 11. On th inner end of block 24 is a guard orholder 30 in the form of a pin fastened at one end to the block and Cap18 serves to hold the fuse plug assembled.

hen a fuse plug as shown in Figs. 1 and 2blows out the fuse materialwill open between contact 16 and spring c0ntact 22 and may beinunediately renewed as follows:First, cap 18 is unscrewed and the fusecarrier removed from the base. The

end of the fuse material will be projecting from cavity 28 and bypulling on it a new length of fuse material will be pulled off roll 29,enough being pulled out to reach along the side of the carrier and overits inner end as shown in Fig. 4c. The end of the material is passedunder guard or holder 30 to hold the material in place. The fuse carrieris then replaced or pushed in the base and cap 18 screwed back intoplace to hold the plug assembled. When the fuse carrier is replaced inthe base, post 13 strikes the fuse material, forces it down into recess27 after the manner shown in Fig. 6 and holds it there. The fuse carrier is replaced in the base in such manner that the fuse material willcome into engagement-with spring contact 22 aud'if desired suitablemeans may be provided to insure the correct insertion. In the presentinstance this is accomplished by providing a projection 31 on thecarrier which fits into a groove 32 in the wall of the base.

The fuse material may be of any suitable shape but preferably I employmaterial in the form of a ribbon of suitable thickness and width to giveit a cross sectional area such that it will burn out under the desiredconditions. The roll of fuse material may be of any suitable sizeto givea desired number ofrenewals, it being only necessary that up a new rollcan be substituted. The current passes through the portion of the fusematerial located between contacts 16 and 22, the 'roll itself'beingoutside the circuit. This is an important consideration as it insuresthat when the fuse burns out the roll 'will be in no way affected ordamaged. It is desirable that the fuse burn out at a point as remote aspossible from theroll of fuse material so as to afford the roll the"greatest degree of protection and to insure this I preferably providethe fuse material a spaced points with sections of diminished crosssectionalarea as indicated at 33, the arrangement being such that asection 33 occurs at about the inner end of the fuse car-- rier when theparts of the fuse plug are assembled. This means then that the fuse willblowout in the lower end of chamber 12 beyond the inner end of the fusecarrier and that the effects of the blow out will be confined primarilyto this portion of chamber 12. In any event, the roll of fuse materialcannot be injured'by a burning out of the fuse: Also. this arrangementprotects the inner contact 16' from being injured by bur ing when thefuse blows.

In renewing the fuse, when cap 18 is screwed down the fuse carrier iswedged tightly into the base block bringing the fuse materialin firmelectrical contact with contacts 16 and 22. Preferably-the telescopingparts are tapered slightly as shown so as to insure a firm engagementbetween adjacent surfaces, V r

From a consideration of the foregoing, it will be seen that my improvedfuse plug is simple in structure, can be manufactured. at

a low cost and the fuse can be quickly and it fit in cavity 28,'and whenone roll is used V a base having a chamber therein, spaced coneasilyrenewed. Also that the fuse plug can be used indefinitely-by providingadditional rolls of fuse material.

In'accordance with the provisions of the patent statutes, I havedescribed the principle of operation of my invention, together with theapparatus which I now consider to represent the best embodiment thereof,but I desire to have itunderstood that the apparatus shown is onlyillustrative and that the invention'inay be carried out by otherIDQFLDS.

What I claim as new and desire to secure by Letters Patent of the UnitedStates,' 1s 1.111 a renewable fuse, the combination of tacts in thechamber, a fuse carrier the inner end of which enters said chamber,a'package of fuse material'carried by the outer end of of which fitssaid chamber in the base, the

outer. end of. said carrier being provided with a cavity, a package offuse material in said cavity, an end, ofsaid fuse material extendingalong the side of the carrier and overthe inner end thereof, and beingin engagement with said contacts, and releasable means for maintainingthe fusecarrier in posltion on the base.

3. in a renewable fuse, a base having a chamber therein, a central postin the-cham- Y her, a contact on the end of the post, a second contactin spaced relation to the firstnamed contact, a fuse carrier which fitsinto said chamber and has a recess to receive said post and a cavity 1nts outer end, a continuous piece of fuse materlal located in said cavityandhaving an end extending along the side ofcthe carrier and into saidrecess and being n engagementiwlth SfllCl contacts,

and means for holding theba'se and carrier.

: .in. assembled position:

In witness :whereof, .I have hereunto set my hand this 10th dayofJanuary, 1923.

, HENRY E. TLER.

